1. Field of the Invention
This invention relates to a mercerizing and/or causticizing wetting agent composition containing alkali metal and/or ammonium salts of 2-ethyl hexyl sulfate, terminally blocked polyethers and, optionally, trialkyl phosphates.
The object of mercerizing and causticizing cotton, i.e. the treatment of cellulose with lyes of different concentration, is to provide the fibers with better gloss effects, with increased receptivity for dyes, greater tensile strengths and a softer, fuller feel. However, the concentrated caustic soda used in practice does not have a particularly high wetting power. In addition, wetting is hindered by the hydrophobic substances adhering to the cellulose fibers. Accordingly, wetting agents are frequently added to the mercerizing and/or causticizing liquors to obtain a fast and uniform reaction of the lye with the cellulose (Chwala/Anger: "Handbuch der Textilhilsmittel", pages347-350, 1977).
Besides having high wetting power, the wetting agents must not cause any foaming in the liquors, must be stable over a wide alkali concentration range and must show very good biodegradability. However, most of the known mercerizing and/or causticizing wetting agents do not effectively satisfy these stringent requirements. For example, the salts of 2-ethyl hexyl sulfate frequently used as wetting agents tend to cause excessive foaming in mercerizing and/or causticizing liquors.
German Pat. No. 12 45 898 describes mixtures of branched-chain carboxylic acid esters, phosphoric acid esters of aliphatic alcohols, fatty acids or soaps and alkoxylated compounds or alkyl sulfuric acid esters as low-foaming wetting agents. In addition, it is known from Chemical Abstracts, Ca 93, 115887 g - (1980) that fatty alcohols alkoxylated with 20 mol of ethylene oxide in combination with 2-ethyl hexyl sodium sulfate improve the wetting power of mercerizing liquors and reduce foaming therein.
Terminally blocked alkyl alcohol ethoxylates are known as foam-reducing additives in low-foaming cleaning preparations from German Pat. Nos. 33 15 951, 37 27 378 and 38 00 490.
The problem addressed by the present invention is to provide low-foaming, alkali-stable and readily biodegradable mercerizing and/or causticizing wetting agents of high shrinkage wetting power.